Inspection of printers and printer output, especially of industrial printers, is performed requiring notable manual labor. Likewise, cameras or scanners are used to assist in printer set up, but these operations typically do not occur inline during regular production.
Presently, line-scan cameras are used on web presses. Web presses operate on large rolls of paper that spool forward (out) and backward (in). The line-scan cameras record the paper roll as it spools out. Once complete, the paper roll is removed and taken to another apparatus known as a re-winder. The re-winder unwinds the paper roll in a play-back inspection to the location of a recorded defect and then enables a human operator to cut out the bad section, re-splice. This process is repeated for each recorded error in the roll.